<?php
/**
 * Class runtime
 * 计算程序耗时工具
 */
class runtime
{
    var $StartTime = 0;
    var $StopTime = 0;
 
    function get_microtime()
    {
        list($usec, $sec) = explode(' ', microtime());
        return ((float)$usec + (float)$sec);
    }
 
    function start()
    {
        $this->StartTime = $this->get_microtime();
    }
 
    function stop()
    {
        $this->StopTime = $this->get_microtime();
    }
 
    function spent()
    {
        return $this->StopTime - $this->StartTime;
    }
 
}

$r = new runtime();
$r->start();
//dosomething
//....
$r->stop();
var_dump($r->spent());